Yoshino can't help but be curious about Yumi, the woman next door who is engulfed in adult charm, so he sneaks into her house. Then, what catches his eye is Yumi, clad only in sexy lingerie and busy with housework. As if to mock the shocked Yoshino, Yumi seduces the man who has come to deliver the package. After catching a glimpse of Yumi's bold behavior, Yoshino decides to ring the doorbell at her house...